Vibroacoustic modeling of the control of aircraft cabin noise using piezoelectric actuators

A vibroacoustic modeling methodology for the simulation of noise transmission into an aircraft cabin previously developed by the authors is extended to include the effect of segmented piezoelectric actuation. The structural model of the aircraft fuselage is based on a stiffened shell theory developed by Egle and Sewall. The strain and kinetic energies of the shell, stringers and frames, and the strain energy for the extensional motion of the floor beams are used in a Rayleigh-Ritz analysis to obtain the structural model. The forcing term due to the acoustic pressure disturbance of the propellers is determined by using virtual work considerations. The passive and active effects of the segmented piezoelectric actuators are incorporated in the model by including their energies in the variational approach. The development of the acoustic model of the cabin reduces to a two-dimensional analysis due to the presence of parallel fore and aft bulkheads. The coupled vibroacoustic model, which includes terms that represent the inherent fluid-structure interaction, is developed from the structural and acoustic modal models. The control performance of the piezoelectric actuators is evaluated by considering the minimization of the sum of the squares of the interior sound field or structural response at a number of finite locations as the control objective. The acoustic and structural responses to one actuator and sensor arrangement are evaluated and discussed.